The invention relates to a coupling for a plug-in connection for media-carrying lines, having a flow channel that has an inner cross-section that is enlarged in steps in order to permit the formation of a reflux zone when carrying the media, and a vent opening.
Plug-in connections are known for connecting media-carrying lines, for example, in the cooling-water and heating lines field, as well as for the use in charge-air systems in motor vehicles. Such plug-in connections comprise a normally standardized connection piece and a coupling with a retaining spring, a retaining ring and a sealing device, which can be connected with the connection piece in a tool-free manner for closing the plug-in connection. A junction, a retaining plate, a receiving device for thermosensors or a separating outlet for gas, for example, are already being integrated in the coupling.
However, known couplings with a separating outlet always have an insufficient separating effect, so that a cooling capacity is reduced, for example, when used in a coolant line.
It is therefore an object of the invention to provide a coupling of the above-mentioned type by which an improved separating performance can be achieved.
This and other objects are achieved by providing a coupling having the characteristic that the step-type expansion is asymmetrically formed over the circumference of the inner cross-section. Therefore, when the media are carried, the formation of a reflux zone can be achieved that is asymmetrical over the circumference of the inner cross-section.
The step-type expansion preferably has an area of minimal expansion and an area of maximal expansion. It is very useful to form no step or only a slight step in the area of minimal expansion. In the area of maximal expansion, the coupling may have a step whose height amounts to approximately 10-60%, particularly approximately 20-50% of the nominal width of the coupling. The nominal width may be the clear width of a line-side end of the coupling or of a connection piece that can be connected with the coupling. Thus, in the area of minimal expansion, a low-loss carrying of the media can take place, and, in the area of maximal expansion, a particularly large and/or dynamic reflux zone can form.
In a preferred embodiment, the vent opening is therefore arranged in the area of maximal expansion. A particularly effective venting can therefore take place.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.